This invention relates to rolling doors, gates and the like and, more particularly, to a support roller to which the rolling doors, gates and the like are secured for rolling up the doors, gates and the like to an opened position and for unrolling the doors, gates and the like down to a closed position, and to a roll-up mechanism provided within the support roller for counterbalancing the weight of the rolling doors, gates and the like when same are being rolled up to the opened position.
Support rollers having roll-up mechanisms for rolling doors, gates and the like are well known in the prior art, such as shown in U.S. Pat. No. 2,520,618 wherein the coil spring is mounted within the support roller. However, the hardware shown in this patent is very expensive and the assembly thereof is time consuming. The diameter of the support roller and the tension of the spring therein is dependent upon the width of the doorway and the weight of the door, gate and the like and, therefore, different diameter support rollers and springs must be stocked for use with the different sized doorways and different weighted doors, gates and the like, thereby increasing the cost of the inventory thereof.
As a matter of interest, U.S. Pat. No. 748,641 discloses an awning roller having a corrugated shape to receive and prevent rotation of a spring block therein while allowing the spring block to slide within the roller when the spring is being wound and unwound to accommodate the variation in the spring length.
U.S. Pat. No. 3,734,161 discloses a door construction having a support drum including end walls with stiffener members disposed therebetween which are shaped in the form of an involute and encircled by a sheet material rigidly secured thereto by fasteners in order to cause the panels of the rolling door to assume a substantially circular configuration when rolled upon the sheet material of the support drum. Here again, the end walls, stiffener members and the sheet material which form the drum are expensive and require a substantial amount of time to assemble.
U.S. Pat. No. 3,732,913 discloses a roll-up slotted shade assembly in which the spring disk and the bearing disk are secured within the barrel by means of screws.
U.S. Pat. No. 4,738,296 discloses a rolling steel door in which a spring module is removably secured within an outer cylinder to facilitate the removal and replacement of a broken or inoperative spring therein.